Incidence of sudden cardiac arrest is higher in areas of low socioeconomic status: A prospective two year study in a large United States community

Background: A potential effect of socioeconomic status on occurrence of sudden cardiac arrest in the community is likely, but has not been evaluated fully. Methods: All cases of sudden cardiac arrest in Multnomah County Oregon (population 660,486; February 2002-January 2004) were identified prospectively and categorized by census tract based on the address of residence and specific geographic location of occurrence of cardiac arrest. Each census tract was assigned to quartiles of median income, poverty level, median home value, and educational attainment. Results: Of 714 cases (annual incidence 54 per 100,000), 697 (98%) had residential addresses that matched a county census tract successfully. For each socioeconomic status measure, the incidence of cardiac arrest was 30-80% higher in the lowest compared to the highest socioeconomic status census tracts. Annual incidence in census tracts in the lowest compared to the highest quartiles of median home value was 60.5 versus 35.1 per 100,000 (RR 1.7, 95% CI 1.4-2.2). This gradient was exaggerated significantly for age <65 years (34.5 versus 15.1 per 100,000, RR 2.3, 95% CI 1.6-3.3). Identical trends were observed for sudden cardiac arrest based on location, with 60% of all cases and 66% of cases age<65 years occurring in the two quartiles with lowest socioeconomic status. Conclusions: Low neighborhood socioeconomic status was associated with a significantly higher incidence of sudden cardiac arrest based on address of residence as well as location of cardiac arrest. For effective deployment of strategies for community-based prevention such as the automated external defibrillator, neighborhood socioeconomic status is likely to be an important consideration.